The present invention relates to an apparatus for dispensing viscous fluids, particularly food products.
In the food service industry, there are a wide variety of devices that are used to dispense viscous food products. Such dispensers are commonly found in restaurants, convenience stores, and other commercial eating establishments. Many viscous products, such as cheese sauces and ice cream toppings, do not flow well at room temperature, so these dispensers are often heated to maintain the product in a flowable condition.
A typical heated dispenser uses a pump, and a connecting nozzle tube to transfer the product from a heated product container housed within the dispenser to the user. The food product travels from the receptacle, through the nozzle tube, and is dispensed by the opening a valve at the nozzle. The use of such a dispensing apparatus, however, has a number of disadvantages. Because the pump, receptacle, and nozzle, are in direct contact with the food product, each must frequently be dismantled and cleaned because of concern over contamination and bacterial spoilage, especially when the dispenser is used with dairy products. Many state health laws often mandate a daily cleaning of dispensers which store and dispense dairy products.
Products most often used in the dispensers become more viscous and tend to congeal as they cool. To properly clean the pump following use, the pump frequently must be soaked to loosen encrusted materials. The shape of the pump often makes it extremely difficult to rid the pump of all particles, thus providing an excellent growth habitat for pathogens. Similarly, the nozzle being of small diameter is difficult to clean. This problem is exacerbated by the prior art devices heating the nozzle during operation causing the food product to strongly adhere to the insides surface of the nozzle. Proper cleaning of the nozzle is difficult because of the collected product build-up and the shape of the nozzle. Moreover, the exterior end of the nozzle, which extends outwardly from the dispenser, is typically comprised of stainless steel, a good conductor of heat. The hot nozzle is capable of injuring the unwary user of the dispenser.
Overall cleaning of the dispenser cannot be accomplished without considerable downtime caused, for example, by withdrawing the pump subassembly from within the product receptacle. Ordinarily, the pump subassembly is located inside the dispenser and has one end of the nozzle tube attached to it. Dismantling of many dispenser parts is required to remove the pump subassembly in order to clean the product receptacle. Any electrical connection, waterproof or otherwise, inhibits this cleaning operation. Finally, the pump, receptacle, and nozzle are in direct contact with the food product; therefore, they must be made of material such as stainless steel that is accepted by the authorities for being in contact with the food product.
Attempts have been made to address some of these concerns by using the bag-in-box technology common in the beverage dispensing industry. For example, soft drink syrups, bulk milk, and wine is packaged in flexible bags. These packages have been successfully used for holding and dispensing liquids which will flow readily at room temperature when the dispensing valve is opened. However, they have not worked well for containing and dispensing viscous products which will not readily flow under the force of gravity.
When bag-in-box packages are used for viscous products, pumps, pressure chambers, or similar equipment is needed to force the food product from the bag. An example of the pressure chamber used with a bag-in-box type of apparatus is found in U.S. Pat. No. 4,796,788, issued Jan. 10, 1989, and assigned to Liqui-Box Corporation. Such dispensers, however, have their own attendant disadvantages, including the expense of moving the food product.
In the aforementioned co-pending and commonly assigned U.S. patent Ser. No. 08/681,186, now U.S. Pat. No. 5,803,317 an alternative system for dispensing viscous food products was introduced that incorporates the use of a peristaltic type of pump. The viscous food product is packaged in a flexible bag having an elongated discharge tube extending therefrom. The dispenser includes a receptacle having an outlet opening in the front, lower portion thereof. The sealed food product container is seated in the receptacle so that the discharge tube extends from the front, lower portion of the receptacle through the outlet opening. The pump is secured beneath the receptacle so that the discharge tube passes through the pump, and cooperates with the discharge tube to provide flow of the food product. The pump described in the co-pending application is a peristaltic pump that uses a rotor which driven at a predetermined speed by an electric motor. A plurality of pinch rollers are mounted on the periphery of the rotor and rotate about axes parallel to the axis of rotation of the rotor. The discharge tube is supported by an arcuate stator positioned near the rotor periphery. Thus, as the rotor rotates, the individual pinch rollers progressively impinge on the discharge tube, compressing the discharge tube against the stator, creating a peristaltic movement of the food product within the discharge tube. In this manner, a predetermined volume of food product is moved axially through the discharge tube and is dispensed at a rate determined by the speed of rotation of the rotor.
In the dispenser described in the aforementioned co-pending application, the food product is heated by conduction through the material of the receptacle including structure encompassing the tube. The portion of the receptacle adjacent the product bag is made of a heat-conducting material and is heated by an electric heater positioned within the dispenser. Additionally, the portions of the dispenser adjacent the discharge tube are made of a heat-conducting material to ensure that product within the discharge tube is also maintained at the proper temperature and that the food material is free flowing at all points within the dispenser, including those portions of the elongated tube most remote from the receptacle. These portions may be heated through conduction from the walls of the receptacle or by a separate heating element.
The heating of the food product by conduction, however, does not always provide optimal uniform heating and may also make the internal and external receptacle surfaces extremely hot. Such hot surfaces increase the difficulty of handling the dispenser.
Therefore, it is an object of the present invention to provide for a viscous food dispenser that heats the food product at all points during the passage of the food product from the receptacle to the point of exit from the receptacle, thereby ensuring the food product remains in a free flowing state.
It is another object of the present invention to provide for a heated viscous food dispenser that reduces the likelihood that a user will come into contact with extremely hot surfaces.
It is a further object of the present invention to provide for a heated viscous food dispenser that provides for more uniform heating of the food product while resident within the dispenser.
It is still a further object of the present invention to provide a receptacle that is easily removed from the dispenser for simple loading of the food product and cleaning.
The foregoing and other objects and advantages will become apparent to those skilled in the art upon a reading of the following description of a preferred embodiment of the present invention.